IR imaging systems employ focal plane arrays in various cameras, having focal plane detectors that are sensitive to light at the 3-5 and 8-12 μm ranges of the optical spectrum. The two ranges cover the two main windows in the IR transmission spectrum of the atmosphere. These systems need to be protected from dazzling and temporary or permanent damage caused by intense radiation sources in the field of view, yet the optical systems should at the same time be completely transparent at these wavelengths for low light power. The intense radiation sources may be of two kinds; first, coherent lasers in the spectral region, continuous or pulsed, and second, non-coherent sources like explosions, field-fire or hot substances in the field of view.